I don't have as much need for tool carts as tool rack on the CNC mills, but for the manual mill and manual lathe I certainly do. I've got two of the older version of these.
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They were half that price and didn't have that side fold up shelf when I bought mine. They are not bad for the $99 on sale at the time. I didn't buy them to be machine tool carts. They were supposed to be project carts. Load one up with the tools, and materials for a job, do the job, and then put everything away. They work great that way. I've done that repairing my tractor, doing electrical in the house, and working on a boat. The problem is now they are dedicated machine tool carts. Not very good ones either. The top bin storage area is a bit of a black hole, but not as bad as the open space on the bottom.
I have one next to the Precision Mathews lathe, and one next to the South Bend mill. Probably I will want a cart for the little turret lathe eventually too.
I've been thinking about something more like this with a wood top added for setting things like vises, rotary tables, similar items off the machine, but still nearby.
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I actually have two of these already joined together with an old butcher block counter top for a work bench in my front office. They are kind of flimsy as metal tool boxes go, but the next step up that is not out of stock is several times more expensive.
I've also been thinking about making my own tool carts with special made locations for tool holders, chucks, and taper tooling. (respectively for each machine). I don't really want to go with a lot larger tool box as a tool cart for each machine, but a couple more drawers for smaller tools and parts might be a better choice.
Just weighing options right now.